LiftMaster and Chamberlain garage door opener: what each blinking light means

LiftMaster and Chamberlain are both Chamberlain Group brands, and both brands’ support links now land on one shared help site that publishes a single diagnostic table for both, so each code has one page here. Openers with UP and DOWN arrow buttons flash a two-number code: count the UP flashes, then the DOWN flashes, and wait for the pattern to repeat to be sure (4 UP then 2 DOWN is code 4-2). Openers without arrows flash the LED beside the Learn button instead. On either kind, the opener’s own lights flashing 10 times means a safety-sensor problem.

The arrows and the Learn button are on the motor unit on the ceiling: a yellow round Learn button means a Security+ 2.0 opener, a white one Security+ 3.0. The two safety sensors sit either side of the door, no higher than 6 inches above the floor, usually on the door tracks; one sends an invisible beam, the other shows a green light while it receives it.

Covers Chamberlain openers too: the two brands share one published table, so each code has one page here.

LiftMaster’s safety line: “Never adjust or loosen the door’s springs, cables, pulleys, or brackets yourself, they’re under extreme tension.” Where a spring, cable or balance problem shows up, its page says to stop and contact a local garage door professional.

The UP and DOWN arrows

1. Code 1-1: 1 UP flash, 1 DOWN flash

   One of the safety sensors is blocked, out of line or unplugged, or its wire is broken. The door starts to close, then reverses.

   2 steps from LiftMaster on its page. A safety-sensor code: only the maker’s alignment and cleaning steps are repeated.

2. Code 1-2: 1 UP flash, 2 DOWN flashes

   The safety sensor wiring is probably reversed or shorted, so the door will not close.

   No step from LiftMaster is repeated here. A safety-sensor code: only the maker’s alignment and cleaning steps are repeated.

3. Code 1-5: 1 UP flash, 5 DOWN flashes

   The opener did not sense the motor turning just after a command, so it hums or clicks and the door barely moves or does not move. LiftMaster notes this does not necessarily mean the motor has failed.

   2 steps from LiftMaster on its page.

4. Code 1-6: 1 UP flash, 6 DOWN flashes

   The opener sensed door movement it did not start, usually because the door is out of balance, or because a door on a jackshaft opener was moved by hand with the emergency release disconnected. The door opens fully, then drifts back down or moves on its own.

   3 steps from LiftMaster on its page.

5. Codes 2-1 to 2-5: 2 UP flashes, 1 to 5 DOWN flashes

   The opener detected a possible fault in an electronic component on its logic board, and does not respond to commands at all. LiftMaster gives all five codes the same meaning.

   2 steps from LiftMaster on its page.

6. Code 3-5: 3 UP flashes, 5 DOWN flashes

   On the wall-mounted jackshaft models, the cable tension monitor sensed slack in a door cable, which LiftMaster treats as a safety hazard. The door reverses to open while it is closing.

   2 steps from LiftMaster on its page.

7. Code 4-1: 4 UP flashes, 1 DOWN flash

   Resistance while closing: the opener sensed an unexpected change in motor speed on the way down, so the door reverses, stops or struggles at any point while closing, not only near the floor.

   3 steps from LiftMaster on its page.

8. Code 4-2: 4 UP flashes, 2 DOWN flashes

   Resistance while opening: the door stops before it is fully open.

   2 steps from LiftMaster on its page.

9. Code 4-3: 4 UP flashes, 3 DOWN flashes

   Motor speed lost while closing: the motor slowed unexpectedly, and the door stops and reverses just before it touches the floor.

   1 step from LiftMaster on its page.

10. Code 4-4: 4 UP flashes, 4 DOWN flashes

    Motor speed lost while opening: the motor slowed unexpectedly and the door stops before it is fully open.

    2 steps from LiftMaster on its page.

11. Code 4-5: 4 UP flashes, 5 DOWN flashes

    The opener does not recognise the travel module installed in it, usually right after a part was replaced, and the door will not move.

    1 step from LiftMaster on its page.

12. Code 5-5: 5 UP flashes, 5 DOWN flashes

    On the wall-mounted jackshaft models, the door ignores the myQ app and schedules (the wall control and remotes still work) because a myQ-compatible light must be installed and paired before the opener will move the door unattended.

    1 step from LiftMaster on its page.

The LED beside the Learn button

1. Learn button LED flashes once

   A safety-sensor problem that stops the door closing: a sensor wire is broken or disconnected.

   2 steps from LiftMaster on its page. A safety-sensor code: only the maker’s alignment and cleaning steps are repeated.

2. Learn button LED flashes 2 times

   A safety-sensor problem that stops the door closing: a sensor wire is shorted, or the black and white wires are reversed.

   2 steps from LiftMaster on its page. A safety-sensor code: only the maker’s alignment and cleaning steps are repeated.

3. Learn button LED flashes 3 times

   A door control fault: the light or screen on the wall-mounted door control is not lit.

   1 step from LiftMaster on its page.

4. Learn button LED flashes 4 times

   The sensors are out of line: the sending sensor works but the receiving sensor’s light is dim or flashing.

   2 steps from LiftMaster on its page. A safety-sensor code: only the maker’s alignment and cleaning steps are repeated.

5. Learn button LED flashes 5 times

   The opener sensed no motor rotation in the first second of a run, which LiftMaster says is usually a mechanical obstruction.

   1 step from LiftMaster on its page.

6. Learn button LED flashes 6 times

   A motor circuit fault. LiftMaster says the motor itself rarely fails and points to replacing the receiver logic board.

   No step from LiftMaster is repeated here.

The opener’s own light bulbs

1. Opener lights flash 10 times

   The opener’s own lights flash 10 times and the door will not close: the safety reversing sensors have a problem.

   2 steps from LiftMaster on its page. A safety-sensor code: only the maker’s alignment and cleaning steps are repeated.

2. Opener lights flash 2 times

   The LOCK feature on the wall door control is on, so the door does not respond as normal.

   1 step from LiftMaster on its page.

semiatic gives no repair instructions of its own; each code page repeats only LiftMaster’s steps.

Find a code by which light flashes and how many times, on any maker’s opener →